Question

我有多维数组，产品组数量超预期

我想按所有这些组的最低计数编号对所有这些组进行排序

作为示例 ：度假后的第一个组将是输入产品组，因为它具有最低计数数，然后是输入产品组..etc

怎么做？

<?php
$a = 
// the output product group
array(
        array('id' => 117, 'name' => 'monitor', 'count' => 60),
        array('id' => 118, 'name' => 'printer', 'count' => 16),
        array('id' => 119, 'name' => 'sound card', 'count' => 19),
// the input product group
  array(
        array('id' => 120, 'name' => 'keyboard', 'count' => 11),
        array('id' => 121, 'name' => 'hard', 'count' => 21),
        array('id' => 122, 'name' => 'mouse', 'count' => 24)
      )
    )

;       
// this code does't works good
// Obtain a list of columns
foreach ($a as $key => $row) {
    $count[$key]  = $row['count'];
}
// Sort the data with mid descending
// Add $data as the last parameter, to sort by the common key
 array_multisort($count, SORT_ASC, $a);

 echo $count[$key];
?>

Answer 1

我对$ a的结构感到困惑。产品120-122位于产品117-119的兄弟阵列内。当然应该有另一个数组包装117-119的“组”？我会假设这是预期的，否则没有意义。那应该是：

$a = array(
    array(
        array('id' => 117, 'name' => 'monitor', 'count' => 60),
        array('id' => 118, 'name' => 'printer', 'count' => 16),
        array('id' => 119, 'name' => 'sound card', 'count' => 19),
    ),
    array(
        array('id' => 120, 'name' => 'keyboard', 'count' => 11),
        array('id' => 121, 'name' => 'hard', 'count' => 21),
        array('id' => 122, 'name' => 'mouse', 'count' => 24),
    ),
);

现在，如果我理解正确，您希望根据组内任何产品的最低计数对组进行排序。您可以使用自定义排序功能执行此操作：

// first calculate the lowest count for each group
foreach ($a as $key => $group) {
    $lowestCount = null;
    foreach ($group as $product) {
        if ($lowestCount === null || $lowestCount > $product['count']) {
            $lowestCount = $product['count'];
        }
    }
    $a[$key]['lowestCount'] = $lowestCount;
}

// sort groups according to their lowest count
usort($a, function($group1, $group2) {
    return $group1['lowestCount'] - $group2['lowestCount'];
});

// clean up the 'lowestCount' variables
foreach ($a as $key => $group) unset($a[$key]['lowestCount']);

输出首先包含120-122组，然后是117-119组，因为11小于16.如果那不是你想要的，请澄清！

编辑：对于旧的PHP（5.2及更低版本），请将排序代码更改为：

// sort groups according to their lowest count
if (!function_exists('groupSort')) {
    function groupSort($group1, $group2) {
        return $group1['lowestCount'] - $group2['lowestCount'];
    }
}
usort($a, 'groupSort');

如何使用子值对多行进行排序

1 个答案: